1. Field of Invention
This invention relates to thermosetting toner and developer compositions and methods by which such thermosetting toner and developer compositions can be prepared and used.
2. Description of Related Art
Conventional toner and developer compositions for xerographic systems are prepared from thermoplastic resins. The molecular weight and structural characteristics, such as the degree of polymerization, polydispersity, segment distribution and branching, of conventional toner and developer compositions have been tuned to optimize fusing requirements and image characteristics. Conventional toner and developer compositions include thermoplastic resins, such as styrene-acrylic or polyester resins, and combinations of one or more pigments, charge control agents, release agents, and other additives, compounded together to yield toner and developer compositions. By selecting various homopolymers and copolymers, conventional toner and developer compositions possessing specific chemical, mechanical and/or triboelectric properties have been prepared.
Numerous processes are known for the preparation of conventional toner and developer compositions. For example, in conventional processes, a resin is melt-kneaded or extruded with a colorant, particularly a pigment, and the product thereof is micronized and pulverized to provide toner particles.
In recent years, greater flexibility in the selection of resin materials and the elimination of attrition and classification steps has been realized thorough the “chemical” fabrication of toners by the controlled, heteroaggregation and accretion of sub-micron resin emulsions and pigment dispersions to directly yield particulate toner compositions. There are several so-called chemical processes for making conventional toner compositions. In aggregation/coalescence processes for making toner particles, such as those described in U.S. Pat. No. 6,309,787, the resin is prepared as a water-based dispersion of sub-micron-sized polymer particles (polymeric latex), which are then aggregated with pigment particles of sub-micron size to the desired toner size and are then coalesced to produce pigmented toner particles. The entire disclosure of U.S. Pat. No. 6,309,787 is incorporated herein by reference.